This invention relates generally to a ramped cap unit for use in combination with an antivortex or safety cover plate of the type installed over a main suction drain of a swimming pool or the like, wherein the ramped cap unit permits a pool cleaner device to travel directly over the ramped cap unit and the underlying safety drain cover plate without interrupting pool cleaning operation, and further without disrupting the antivortex and safety functions of the underlying safety cover plate.
Pool cleaner systems and related devices are generally well known in the art for use in maintaining residential and commercial swimming pools in a clean and attractive condition. In this regard, swimming pools conventionally include a water filtration system equipped with a pump for drawing or suctioning water from the pool for circulation through a filter canister having filter media therein to remove and collect water-entrained debris such as leaves and twigs as well as fine particulate including sand and silt. In a typical arrangement, at least a portion of the pool water is vacuum-drawn over a weir mounted within a so-called skimmer well positioned substantially at the water surface to draw and collect floating debris to the filter equipment, while another portion of the pool water is vacuum-drawn to the filter equipment through at least one so-called main suction drain located in the pool floor typically at a deep end thereof. From the filter canister, the water is recirculated to the pool via one or more return lines. Such filtration equipment is normally operated for several hours on a daily basis and serves, in combination with traditional chemical treatments such as chlorination or the like, to maintain the pool water in a clean and clear sanitary state.
The water filtration system is generally ineffective, however, to filter out debris which settles onto submerged floor and side wall surfaces of the swimming pool. In the past, settled debris has typically been removed by coupling a vacuum hose to the suction side of the pool water filtration system, such as by connecting the vacuum hose to the skimmer well located near the water surface at one side of the pool, and then manually moving a vacuum head coupled to the hose over the submerged pool surfaces to vacuum settled debris directly to the filter canister where it is collected and separated from the pool water. However, manual vacuuming of a swimming pool is a labor intensive task and is thus not typically performed by the pool owner or pool cleaning service personnel on a daily basis.
So-called automatic pool cleaner devices have been developed over the years for cleaning submerged pool surfaces, thereby substantially eliminating the need for labor intensive manual vacuuming. Such automatic pool cleaners typically comprise a relatively compact cleaner housing or head coupled to the pool water filtration system by a hose and including water-powered means for causing the cleaner to travel about preferably along a random path within a swimming pool to dislodge and collect settled debris. In one form, the pool cleaner is connected to the return or pressure side of the filtration system for receiving positive pressure water which powers a turbine for rotatably driving cleaner wheels, and also functions by venturi action to draw settled debris into a filter bag. See, for example, U.S. Pat Nos. 3,882,574; 4,558,479; 4,589,986; and 4,734,954. In another form, the pool cleaner is coupled by a vacuum hose to the suction side of the filtration system, whereby water is drawn through the pool cleaner to operate a drive mechanism for transporting the cleaner within the pool while vacuuming settled debris to the filter canister of the pool filtration system. See, for example, U.S. Pat. Nos. 3,803,658; 4,023,227; 4,133,068; 4,208,752; 4,643,217; 4,679,867; 4,729,406; 4,761,848; 5,105,496; 5,265,297; and 5,634,229. See also, copending U.S. Ser. No. 09/090,894, filed Jun. 4, 1998, and 09/176,532, filed Oct. 21, 1998.
In addition, in recent years, antivortex or safety cover plates have been developed for covering suction drains in a swimming pool or spa to reduce or eliminate the risk of suction-entrapment of a swimmer, particularly by suction-entrapment of a swimmer""s hair or clothing. More specifically, the water filtration system pump is normally designed to draw water to the filtration equipment at a substantial flow rate and thus has the capacity to develop a significant suction or vacuum within filtration system flow lines. If a significant portion of the flow area of a suction drain is obstructed by a swimmer""s hair or clothing or portion of the body while the filtration system is operating, the swimmer can be vacuum-drawn and retained at the drain with a substantial force to result in suction-entrapment of the swimmer and creating a risk of drowning. To safeguard against suction-entrapment accidents, many swimming pools are being constructed or retrofitted with an antivortex safety drain cover plate mounted over each pool suction drain and defining a geometric array of spaced-apart vents positioned to reduce or eliminate the risk of any significant portion of the vents being obstructed by a swimmer at one time.
Unfortunately, such safety drain cover plates typically project upwardly a short distance from the pool floor to define the multiple vents which may open in different directions, whereby the cover plate provides a raised obstruction to a pool cleaner as it traverses submerged pool surfaces to perform its desirable cleaning functions. In this regard, the pool cleaner can become trapped against the raised cover plate to interrupt normal cleaning operation.
The present invention relates to a relatively simple yet effective ramped cap unit for installation into a swimming pool in a position overlying an upstanding safety drain cover plate, wherein the cap unit is contoured to permit a pool cleaner to climb and travel directly thereover for uninterrupted cleaning operation, and further wherein the cap unit includes a large plurality of open flow vents to permit downward water flow therethrough substantially without disrupting the antivortex and safety functions of the underlying drain cover plate.
In accordance with the invention, a ramped cap unit is provided for installation into a swimming pool in a position covering a main pool drain equipped with an upstanding antivortex safety drain cover plate, wherein the ramped cap unit has a smoothly contoured shape to permit a pool cleaner device to travel thereover without interrupting or obstructing cleaning operation.
The ramped cap unit comprises a generally inverted saucer defining a smoothly sloping and convex or ramped upwardly presented surface having a diametric size and shape to fit over the safety drain cover plate. An array of ribs formed on the underside of the cap unit engage an outer periphery of the upstanding cover plate to retain the cap unit in position thereon, and to define a downwardly open central cavity into which the upstanding antivortex safety cover plate is nestably received. A large plurality of vents are formed in the cap unit at spaced-apart locations to permit downward water flow therethrough substantially without disrupting the antivortex and safety functions of the underlying drain cover plate. The ramped upper surface of the cap unit permits a pool cleaner device to climb directly over the cap unit in the course of pool cleaner travel over submerged pool surfaces to collect and dislodge particulate debris settled thereon.
In a preferred configuration, the ramped cap unit comprises a central disk having a size and shape corresponding generally with the size and shape of the safety cover plate. The central disk is assembled with an outer annular ring which may by formed from an assembled plurality of part-circle ring segments. Each ring segment has a plurality of vents formed therein to permit downward water flow therethrough to the underside of the annular ring into a plenum chamber in flow communication with vents formed in the safety cover plate. The annular ring tapers radially outwardly and downwardly from the central disk to an outer perimeter disposed substantially flush with the pool floor.
Other features and advantages of the present invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.